I have no idea -I have only had one a few weeks ago in hospital.
Had an operation on my eye and was told in rare possibilities, your nose bleeds.

Of course I was sitting up the next day and felt drip, drip, drip and thought my nose was running!
Looked down and bed was covered in blood.
Eventually they brought me a thing -a wad of something, that clipped behind my ear and caught the blood!

And having had an anesthetic I now cannot remember if they told me to do anything!